A unique antifoam/defoamer composition is provided having concentrated active ingredients, such as a polyether surfactant and a polyhydric alcohol fatty acid ester. This composition is particularly advantageous for foam control and drainage enhancement in the following applications; paper and pulp processes, general wet-end foam control, groundwood/mechanical pulp systems, secondary fiber systems, and bleach plants/screen rooms.
Foam is consistently a problem in the processing of pulp during the manufacture of paper products. Virtually all segments of the papermaking process generate entrained air and surface foam which are extremely undesirable due to their deleterious effect upon process efficiency and the finished product.
A variety of antifoam/defoamer agents have been used with varying degrees of success. Many defoamers are stearic acid or fatty acid based emulsion products. Some examples of stearic acid based emulsion products are set forth in the following patents: U.S. Pat, Nos. 3,705,860 (Duvall), issued Dec. 12, 1972, and 3,337,595.
Typical fatty acid based emulsion products are described in the following Patents: Great Britain Patent Appl. No. 81/29520 (Flannigan), filed Sept. 30, 1981, European Patent Appl. No. EP 76558 (Flannigan), filed Apr. 13, 1983, French Pat. No. 1557086, issued Feb. 14, 1969, German Patent Appl. No. DE 3013292 (Perner et al.), published Oct. 15, 1981, and U.S. Pat. No. 4,451,390 (Flannigan), issued May 29, 1984.
Antifoam products are usually sold in diluted form causing them to be bulky and costly to transport. These defoaming agents may also contain undesirable particulate additives which may deposit throughout the papermaking process resulting in undesirable deposits throughout the system. Particulate additives which may cause deposits and plugging of papermaking systems are typically stearic acids, fatty acids, silicones, hydrophobic silica, waxes or other organic particles.
Other examples of defoamer agents which contain particulate additives, such as silicone, hydrocarbons or other organic particles, are as follows: Great Britain Patent Appl. No. 2,094,330 (Topfl et al.), filed Sept. 15, 1982, German Patent Appl. No. 2,625,707 (Abel et al.). published Dec. 23, 1976, Japanese Patent Appl. No. 50,404/79 (Hirakimoto et al ), published May 14, 1979, and Rumanian Patent Appl. No. 111,852 (Deac et al.). filed Aug. 5, 1983.
The present inventor has developed a unique antifoam/defoamer composition which substantially reduces transportation costs and overcomes deposition problems associated with the aforementioned defoaming agents. It avoids the problems associated with conventional antifoam products by forming a concentrate of active ingredients, such as a polyether surfactant and a polyhydric alcohol fatty acid ester, without any oil, amide, hydrophobic silica or silicone additives.
The use of glycols or glycerols as foam inhibiting agents is described in rhe following patents: Japanese Patent Appl. No. 79/59404 (Hirakimoto et al.), published May 14, 1979, French Pat. No. 2,049,783 (Seizinger), granted Apr. 30, 1971, French Pat. No. 1,557,086, granted Feb. 14, 1969, and Japanese Patent Publication No. 75/005,157, published Feb. 28, 1975.
Hirakimoto et al. describe a defoaming agent which includes a polyether with a molecular weight of 2000-16,00, the polyether being prepared by polymerization of ethylene oxide (5-30 parts) and propylene oxide (95-70 parts) and reaction with a polyol, such as glycerol or sorbitol; 2-ethylhexyl alcohol; and a paraffin oil.
Seizinger describes a nonionic, biodegradable foam inhibitor used in detergents, latexes, and paper manufacturing. The inhibitors are prepared from mixtures of alkylene oxide, glycol, and a polymer catalyst. The catalyst is prepared by heating glycerol in KOH, removing water, and adding propylene oxide under nitrogen. The oxide/glycol/catalyst mixture was thereafter heated, and the catalyst was removed to give a yellow liquid inhibitor.
French Pat. No. 1,557,086 describes an antifoaming agent for use in foam prevention by reaction products with block polyethylene-polypropylene glycols and polyols.
Japanese Patent Publication No. 75/005,157 describes a defoaming agent containing a higher aliphatic ester compound and emulsifier for use in papermaking, fiber, paint, and fermentation industries.
The present invention is a concentrated, active, emulsifiable product which has many cost saving advantages over conventional defoamers. Being a pure active ingredient, the defoamer of the present invention has no base or carrier resulting in reduced transportation and container costs. Furthermore, the fact that this defoamer is not an oil-based defoamer assists in preventing the loss of paper sheet properties, such as brightness, sizing efficiency and strength. Having no oil, amide, hydrophobic silica or silicone additives prevents deposition and felt filling. It has also been discovered that the defoamer composition of the present invention is a much more effective agent for control of entrained air than conventional defoaming agents. Additional advantages of the present invention shall become apparent as described below.